Department of Pediatrics, University of Washington, Seattle, WA, USA.
Diabetes Technol Ther. 2013 Aug;15(8):628-33. doi: 10.1089/dia.2013.0036. Epub 2013 Jul 5.
Most current model-based approaches to closed-loop artificial pancreas systems rely on mathematical equations describing the human glucoregulatory system; however, incorporating the various physiological parameters (e.g., illness, stress) into these models has been problematic. We evaluated a fully automated "fuzzy logic" (FL) closed-loop insulin dosing controller that does not require differential equations of the glucoregulatory system and allows clinicians to personalize dosing aggressiveness to meet individual patient requirements.
This pilot study evaluated the FL controller in the setting of bed rest in a very controlled environment. Two carbohydrate-controlled meals were given (30 g at 8 a.m. and 60 g at 2 p.m. without meal announcement or premeal bolus. The primary end point of the study was avoidance of hypoglycemia, defined at <60 mg/dL. Multiple end points related to the frequency and severity of hyperglycemia and hypoglycemia were also assessed.
Of the 12 subjects we recruited, 10 were enrolled, and seven completed the study. Two of the enrolled subjects were discontinued because of hypoglycemia; the other was discontinued because of sensor failure. Seven of the 10 subjects who completed the study had average blood glucose values of 165 mg/dL and were within a specified target blood glucose range (70-200 mg/dL) for 76% of the 24-h study period.
Our findings suggest that the FL controller provides a viable alternative to model-based controllers as a component of a closed-loop insulin delivery system. Furthermore, our FL controller allows clinicians to easily specify the level of glucose control based on each patient's clinical needs.
大多数基于模型的闭环人工胰腺系统方法都依赖于描述人体血糖调节系统的数学方程；然而，将各种生理参数（例如疾病、压力）纳入这些模型一直存在问题。我们评估了一种完全自动化的“模糊逻辑”（FL）闭环胰岛素给药控制器，它不需要血糖调节系统的微分方程，并允许临床医生根据个体患者的需求个性化给药强度。
这项初步研究在非常受控的环境中评估了卧床休息期间的 FL 控制器。给予了两次碳水化合物控制的餐食（8 点 30 克，2 点 60 克，没有餐食通知或餐前 bolus。该研究的主要终点是避免低血糖，定义为<60mg/dL。还评估了与高血糖和低血糖的频率和严重程度相关的多个终点。
在我们招募的 12 名受试者中，有 10 名入组，其中 7 名完成了研究。两名入组的受试者因低血糖而被停用；另一名因传感器故障而被停用。在完成研究的 10 名受试者中，有 7 名受试者的平均血糖值为 165mg/dL，并且在 24 小时研究期间的 76%时间内处于规定的目标血糖范围（70-200mg/dL）内。
我们的发现表明，FL 控制器作为闭环胰岛素输送系统的组成部分，为基于模型的控制器提供了一种可行的替代方案。此外，我们的 FL 控制器允许临床医生根据每个患者的临床需求轻松指定血糖控制水平。
